Heat treating device



April 16, 1940.

E. R. GRAVES ET AL HEAT TREATING DEVICE 4 Sheets-Sheet 1 Filed June 25,1938 6- WHU v Ap 16, 1940., R. GRAVES IETAL HEAT TREATING bEvIcE 4Sheets-Sheet 2 Filed June 25, 1938 April 9 E. R. GRAVES EI'AL Q 2,197430 HEAT TREATING DEVICE Filed June 25, 1938 4 Sheets-Sheet 3 April 16,1940. E. R. GRAVES ET AL HEAT TREATING DEVICE Filed June 25, 1933 4Sheets-Sheet 4 Min H 1 I Hu n wuw. U

ER. F

Patented Apr. 16, 1940 HEAT TREATING DEVICE Earl R. Graves, Riverside,and Clayton S. Powell and Frank J. Kubalanza, Chicago, and Walter H.Voigt, Maywood, Ill., assignors to International Harvester Company, acorporation of New Jersey Application June 25, 1938, Serial No. 215,824

4 Claims.

This invention relates to a device for heattreating a steel part orelement. More particularly the invention relates to a device forelectrically heat-treating an element by passing the same through atleast a pair of spaced, current-conducting members formed to engage theelement and to heat-treat the same in accordance with the properties ofthe element and with the results desired; and, also to supply aquenching medium to the portion so treated at a point or points andwithin a space of time also in accordance with the properties of theelement and the results desired.

The invention contemplates principally a means for electricallyheat-treating an element in a desirable and efficient manner, preferablythrough the use of a pair of spaced, currentconducting rollers betweenthe peripheries of which the element is passed in a linear path, therollers being so formed as to concentrate current along a predeterminedportion of the element.

Each roller preferably employed in a suitable device is considerablylarge as compared to the thickness of the portion of the element to betreated thereby. Since the roller is large and has a considerable mass,it has a tendency, because of its inherent properties, to coolprematurely portions of the thickness of the element while excessivelyheating other portions.

sirable, it is important, and a principal object of the invention, thatthe peripheries of the rollers be formed with current-concentratingportions. Another object of the invention, and similarly important anddesirable, is the provision of a plurality of heat-treating means in theform of units, each comprising a pair of spaced currentconductingmembers for heat-treating opposite portions of the element withoutincreasing the number of steps in the operation.

Another important object is to provide a simple and efficient means forcarrying the element in its path between the members.

Another object is to provide, when the element consists of a pair ofopposite edges each of which Another object is to provide means foremciently changing the position of the element as 0 above.

Since the result of such treatment is unde- Still another object is toprovide means for supplying a quenching medium to the treated portionsof the element substantially immediately after portions pass through andare treated by respective heat-treating members.

And still another object is to direct the flow of the quenching mediumwith respect to the portion treated.

Briefly and specifically, these and other desirable objects of theinvention may be achieved by the device and in the manner chosen for thepurposes of illustration, in which a steel part or element has a portionthereon of substantially uniform thickness, which is to be heat-treatedalong a certain width thereof. The element is mounted on a conveyer orcarrying means which operates in a linear path alongside the faces of apair of current-conducting members, such as rollers or the like. Theperipheries of the rollers are formed with. current-concentratingportions in the form of a plurality of spaced annular ribs. As thecarrying means moves in its linear path, the portion on the element tobe treated is passed between the peripheries of the rollers, and throughthe medium of the annular ribs current is concentrated throughout theportion the flow of quenching medium through the slot in the pipe.

A further understanding of the objects, construction and importantfeatures of the invention will be had from the following detaileddescription, of a preferred device, taken in conjunction with theaccompanying sheets of drawings illustrating the same.

In the drawings:

Figure 1 is a plan elevational view of a suitable device as referred toabove;

Figure 2 is a side elevational view of the same with a portion of thesupporting means for one pair of rollers omitted;

Figure 3 is an end elevational view in section of one of the supportingmeans for a pair of spaced current-conducting rollers, the view beingtaken substantially along the line 33 of Figure 1 and showing theposition of the rollers with respect to the element to betreated;

Figure 4 is a somewhat reduced sectional view taken substantially on theline 4-4 of Figure 3, and showing the mounting of the bearing for thelower roller in the supporting structure;

Figure 5 is a front elevational view of one of the supporting means withthe current-conducting rollers removed;

Figure 6 is an enlarged longitudinal sectional View through the memberfor carrying the element to be treated; and,

Figure '7 is a transverse sectional view of the same showing the meansfor limiting the movement of the carrying member with respect to thecarrying means.

The device embodied in the particular construction of the invention asillustrated in the drawings includes a base or table NJ, on which ismounted a motive means, such as an electric motor H, which isoperatively connected through reduction worm gearing, contained in thehousing 12, to drive a shaft 53. The shaft I3 is rotatably supported ina pair of spaced brackets or bearings l4 rigidly secured to the base ortable I G. The table it also has rigidly secured thereto at a pointspaced longitudinally from the bearings M, a second pair of bearings orbrackets IS, in which is rotatably carried a shaft IS. The shafts I3 and[6 are disposed in parallel relation, the former being driven by themotor H and both being provided with sprockets 11 about which is traineda link-belt type chain l8. The chain l8 and the sprockets IT, as drivenby the motor H, constitute a conveying or carrying means for carryingalong a linear path an element to be heat-treated. This element will belater described.

A heat-treating unit generally designated by the numeral [9 is rigidlycarried by the base ill at one end thereof and at one side of theconveyer chain 18. A second heating unit, generally designated by thenumeral 20, is rigidly carried by the base It] adjacent the other endthereof and at the opposite side of the conveyer chain I 9. These unitsare substantially identical in construction and it will be understoodthat the detailed description of one will apply similarly to the other.The construction of one partcular type of heating unit is best shown inFigures 3,

, 4 and 5. Each heating unit embodies a structure comprising a pair ofspaced vertical walls 2|. These walls are welded or otherwise secured tothe base or table It), and a second pair of walls 22 spaced in adirection at right angles to the walls 2| rigidly cross-connects thesewalls, as best shown in Figure 4. The construction is such as to providea vertical slideway, which, since the walls are preferably of metal, isinsulated by a plurality of insulating strips 23. At the lower portionof the structure and resting on the base it] is rigidly disposed a metalblock 24. A slide block or bearing 25 is fitted into the verticalguide-way and preferably remains stationary with respect to thestructure, resting on the insulated upper portion of the block 24. Asecond slide block or bearing 26 is slidably carried by the structure inthe upper portion of the vertical guide-way and is prevented fromfurther downward movement by an adjusting means carried by a portion 21of one wall 2!. This adjusting means comprises a boss or bearing portion28 rigidly carried by the portion 21. The boss 28 is provided with anaxial bore which movably carries therein a shaft 29. This shaft extendshorizontally into the vertical guide-way and at its inner end isprovided with an eccentric portion 30 and at its outer end with anadjusting arm or handle 3!. The eccentric portion 30 engages a strip ofinsulation material 32 carried on the under side of the slide bearing26.

Each of the walls 22 is provided at its upper end with a verticallyextending member or bolt 33. A transverse member 34 is rigidly carriedby the bolts 33 and extends horizontally across and above the upperslide bearing 26. This cross member 34 operatively carries one end of atensioning means in the form of a coil spring 35, the lower end of thespring being fitted in a cup 36 formed of insulation material disposedin a recess in the upper portion of the upper slide bearing 28. Thismeans tends to urge the slide bearing 25 downwardly against theeccentric portion 30 on the rod 29 of the adjusting means.

As best shown in the sectional view in Figure 3, each of the slidebearings 25 and 25 rotatably carries a shaft 37 disposed on an axis atright angles to the planes of the vertical walls 2! and also to theplane of the linear path made by the conveyer chain 18. Each shaft atits end adjacent the conveyer chain [8 carries for rotation therewith aroller 38. Each roller 38 is preferably formed of copper alloy and isremovably secured to a portion of the shaft 3'! by a plurality of bolts38. The removability of the rollers is desirable from the standpoint ofreplacing them as they are worn from usage. Through the medium of theinterposition of the adjusting means for the upper slide bearing, theupper roller 38 is ad justably spaced vertically above the lower roller.It is through this space between the peripheries of the rollers that theelement to be heat-treated is passed.

The type of element chosen for the purposes of illustration and forwhich the present invention is especially adapted is a section of aknife or cutter bar of a standard mower or harvesting machine. Thissection or element has opposite flat surfaces and is of a substantiallyuniform thickness, having opposite edge portions along which the cuttingedges of the section are formed. It is desirable that these edges beproperly heattreated before sharpening, and, at the same time, it isdesirable to retain an untreated or soft portion in the center of thesection. The disposition of this soft portion is especially important instrengthening the section, being further desirable to permit holes to bedrilled therethrough for the purpose of attaching the section inposition on a knife. Breakage of the section is thus prevented at pointsadjacent the holes. The element or section will hereafter be generallydesignated by the numeral 39 and the opposite edge portions, angularlyrelated, by numerals 40 and 4|. It is along these edges 40 and 4! thatthe section must be heat-treated for providing hardened wear edgesenabled to withstand continued a usage. It is desirable to heat-treatthese por tions along paths of predetermined widths.

It will be appreciated from the foregoing description that theinvention, as embodied in the construction set forth, is not limited inscope to its adaptation to heat-treating the specific sections defined,namely the mower or harvester knife sections, nor to the specificheating devices referred to. Any type of element having similar portionsmay be so treated by a similar device especially adapted thereto withinthe scope of the invention.

In the present adaptation of the invention, the knife section 39 iscarried by the conveyer chain l8 through the medium of means in the formof a carrying member 42. This member 42 is movably mounted with respectto the chain l8, and, as best shown in Figures 6 and 7, a particulartype of link 43 is provided for mounting the member. This link has across-connecting horizontal portion 44, to which the carrying member 42is pivotally carried by a pivot pin 45. This construction permitsswinging movement of the carrying member with respect to the chain l8.The member is formed with a holding portion or pocket 46 into which anend portion of the knife section fits, and there is no relative movementbetween the section and the carrying member. As best shown in Figure 1,it can be readily seen that the carrying member at its forward portionis cut away and is substantially narrower than the forward portion ofthe knife section 39. The portions 48 and 4| of the section'therebyextend beyond the sides or edges of the member 42, and permit passage ofthe portions between the rollers 38 without interference from thecarrying member. The carrying member is further provided with a pair ofdownwardly extending spaced pins 41, which are disposed adjacentopposite sides of the link member 43. These pins provide a means forlimiting movement of the carrying member with respect to the chain. Froman examination of Figures 1 and 7, it will be seen that these pinsengage respective side portions of the conveyer chain l8 to confineswinging movement of the member 42 to movement within predeterminedlimits.

Starting at the left hand side of Figure 1, it will be noted that themember 42, carrying the knife section 39, is moved to a position with apin 4! engaging one side of the chain l8, so that the portion of thesection along the edge 48 is disposed substantially along a lineparallel to the linear path described by the conveyer chain. In thisposition, the conveyer chain will move the knife section 39 along thelinear path with the portion along the edge 48 passing between thespaced rollers 38 in the left hand heating unit l9. Current conductors48 and 49 are connected to the bearing members 25 and 26 to supplycurrent to the rollers. Similar conductors are provided for the righthand heating unit 28. The insulating strips 23, previously described,prevent shorting of the parts in the heating unit structure.

In order properly to support the carrying member and section as thesection is passed between the rollers 38, there is provided a supportingor guide member 50, best shown in Figures 1 and 3. The member 50 isrigidly carried by the inner wall 2| of the heating unit structure, andthe carrying member is adapted to be supported on this member as itpasses thereover for maintaining the proper position of the knifesection 39 with respect to the rollers 38.

As best shown in Figures 1 and 2, a pipe 5| including a horizontalportion 52 is located in close proximity to the faces of the rollers 38and closely at the right hand side of the vertical line intersecting thecenters of the rollers. The left hand end of the pipe is closed and oneside of the horizontal portion 52 is formed with an elongated opening ora slot 53. This pipe provides means for supplying a quenching medium tothe portion of the section substantially immediately after it passesthrough the rollers 38. It will be noted that, when the quenching mediumis continually supplied, it will be directed through the slot 53 to thesection in proportion to the extent that the portion along the edge 48is heated and leaves the rollers.

At the right hand side of Figure 1, the heating unit 20 is, aspreviously mentioned, disposed at the opposite side of the conveyerchain l8. In this position, the current-conducting rollers 38 thereonare adapted to treat the opposite portion of the section along theopposite edge 4| thereof. Passage of the portion along the edge 4|between the rollers 38 of the heating unit 28 is similar to the passagealong the edge 48 between the rollers 38 of the heating unit l9.

Since the edge 4| is on the opposite side of the section from the edge48, it is desirable that means be provided for changing the position ofthe element with respect to the conveyer chain It, so that the portionalong the edge 4| is disposed along the linear path of the conveyerchain |8 whereby it may be treated by the rollers of the heating unit28. For this purpose the carrying member 42, of which there may be aplurality on the chain 8, is formed with a pair of oppositely disposedcut-out or notched portions 54 and 55. To change the position of thecarrying member and element from the position shown at the left handside of the figure to that at the right hand side of the figure,'anengaging member in the form of an arm 56 is secured to the inner wall 2|of the heating unit structure 20. This arm is formed with an engagingportion 51, which lies in a transverse plane at right angles to theplane of the linear path described by the chain l8. As the chain carriesthe carrying member and element from left to right, the engaging portion51 of the member 56 engages the carrying member in the notch 54, as bestshown in dotted lines in Figure 1. Continued linear movement of thechain from left to right moves the carrying member and element to theposition shown at the right hand side of the figure. The pin 41 at thatside of the member engages the respective side of the conveyer chain I8,and thus limits movement of the carrying member and element within thepredetermined limits, whereat the portion along the edge4| is disposedsubstantially along a path parallel to the linear path of the chain I8.A quenching medium supply means 58 is associated with the heating unitstructure 28 and is similar in construction and arrangement to thequenching medium supply means for the heating unit structure l9. Asimilar guide or supporting means 59 is also provided and is rigidlycarried by the inner wall 2| of the heating unit structure 20 forsupporting the carrying member 42 for maintaining the proper position ofthe element with respect to the rollers 38 on that unit.

After opposite side. portions of the section have been treated by bothunits, the section is permitted at the extreme right hand end of theconveyer chain |8 to drop from the carrying member into any suitablereceptacle or the like. The carrying members are then carried along thelower run of the chain [8 and in order to dispose them with respect tothe chain in a manner whereby the portion along the edge 40 of anothersection 39 may be treated, a means 68, similar to the means 56, isassociated with the left hand heating unit l9 and is formed with anengaging portion 6|, which engages the carrying member 42 in the notch55, as the conveyer chain carries the member 42 along its lower run. Aseach carrying member 42, thus positioned, approaches.

at the left hand end of the chain l8, an untreated ha been provided atits periphery with a plurality of current-concentrating portions in theform of axially spaced annular ribs 62. Through the provision of thismeans, the current is thus concentrated throughout the portions of thesections along either of the edges 40 and 4| and the intermediateportion of the section remains thus untreated or soft. The provision ofthe annular ribs possesses important significance in view of the factthat lack thereof would permit uneven treatment of the portions to betreated. Because of the comparative large mass of each roller, it has atendency to become cooled and thus it cools the surface of the portionto be treated. The result would be that opposite surfaces of the portionwould become prematurely cooled while an inner portion would remain hot,thus giving the cross-section of the knife section an imdesirablestratified result. This undesirable result is obviated by the provisionof the current-concentrating ribs 62, which insure uniform dispositionof heat throughout the thickness of that portion of the knife sectionlying along either of the edges 40 or M. The provision of the tensioningmeans including the coil spring 35 insures constant contact of therollers 38 with the portions of the sections to be treated and alsoallows for any irregularities along the surface thereof. Varyingthicknesses of sections are provided for by the adjusting meanscomprising the shaft 29, the eccentric portion 30 and the lever orhandle 3|.

From th foregoing description, it will be seen that one form of adesirable device has been provided, in accordance with the invention,for heattreating one particular type of element, and that variousprovisions have been made for properly heating and quenching the elementin accordance with the results desired to be obtained. It will beunderstood, of course, that various changes may be made in the device tocompensate for changes in the properties and results desired from theelements to be treated. It will be still further understood thatnumerous other alterations and modifications may be made in theconstruction of the device, as illustrated, Without departing from thespirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a device for electrically heat-treating a substantially uniformlythick element having opposite surfaces along each of two angularlyrelated portions, the combination of conveying means movable along ahorizontal, linear path, a carrying member movably carried by said meansand positionable with respect thereto substantially about a verticalaxis, said member adapted to carry the element horizontally in either oftwo positions, in one position with one aforesaid portion arranged alongthe linear path, a pair of current-conducting rollers carried onvertically spaced horizontal axes alongside the conveying means, saidconveying means moving the said portion of the element between therollers with the peripheries of the rollers engaging respective surfacesthereof, means disposed adjacent the conveying means and spaced from therollers, said means adapted to cooperate with the carrying member formoving same to the other of the aforesaid positions to dispose the otherportion of the element along the linear path, and a second pair ofcurrent-conducting rollers carried similarly alongside the conveyingmeans and spaced along the linear path from the last named means forsimilarly treating said other portion.

2. In a device for electrically heat-treating an element having oppositesurfaces along each of two angularly related portions, the combinationof means movable along a linear path and including a member for carryingthe element, said element being mounted on the member and positionablelaterally with respect to the carrying means for disposing first oneportion along said path at one side of said means and then the otherportion along the path at the other side of the means, two pairs ofcurrent conducting members located at opposite sides of and spaced fromeach other along said means, and means disposed adjacent said linearpath cooperable with the element to position same from one side of themeans to the other, the carrying means passing one portion of saidelement between one pair of conducting members and then the otherportion between the other pair of members.

3. In a device for electrically heat-treating a Section of a harvesterknife, in which the section is substantially triangular and has oppositesurfaces along each of two sides to be treated, a carrying means movablealong a linear path and including a member for carrying the section,said section being laterally positionable on the carrying means fordisposing first one side of the section and then the other along thelinear path at opposite sides of the carrying means, a treating means atone side of the carrying means for treating one side of the section, asecond treating means spaced from the first treating means and disposedalong the path at the other side of the carryin means, and meansdisposed intermediate the treating means for positioning the section onthe carrying means to arrange the sides along the path to pass and betreated by the respective treating means.

i. In a device for heat-treating an element having angularly relatedportions to be treated, a flexible conveying means movable along alinear path and including a member for carrying the element, saidelement being carried by said memher for lateral swinging movement fromone side of the conveying means to another to dispose the portions ofthe element successively along the path, a heat-treating means at oneside of the conveying means, a second heat-treating means at the otherside of the conveying means and spaced along said path from the firstheat-treating means, said heat-treating means being adapted,respectively to treat the portions of the element, each treating meansincluding a pair of heating rollers having their peripheries spacedsubstantially the thickness of the element, each means further includinga guide means cooperating with the conveying means and element to guidethe element between the rollers, and means positioned intermediate thetreating means and cooperable with the element for swinging the elementlaterally on the conveying means after one portion of said elementpasses between the rollers of one treating means to dispose the otherportion of the element along the path for passage between the rollers ofthe other treating means.

EARL R. GRAVES. CLAYTON S. POWELL. FRANK J. KUBALANZA. WALTER H. VOIGT.

